Method of roll-forming metal product



June 1, 1965 w. N. FLETCHER 3,186,059

7 METHOD OF ROLL-FORMING METAL PRODUCT Original Filed Oct. 2'7, 1961 4Sheets-Sheet 1 II I l INVENTOR.

# rms/s1 June 1, 1965 w. N. FLETCHER 3,186,059

METHOD OF ROLL-FORMING METAL PRODUCT Original Filed Oct. 2'7, 1961 4Sheets-Sheet 2 14 J0 Z 4% 40 Q7) /4 1 LL 7 f3 INVENTOR. I;

June 1, 1965 w. N. FLETCHER 3,185,059

METHOD OF ROLL-FORMING METAL PRODUCT Original Filed Oct. 27, 1961 4Sheets-Sheet 4 INVENTOR. 14 77/2177? A! f/efzXar arms/ United StatesPatent 3,186,059 METHOD 9F RULL-FQRMENG METAL PRGDUCT William N.Fletcher, Lathrup Village, Misha, assiguor to 'Iernes Steel Company,lloseviile, Mich, a corporation of Michigan Uriglnal application (let.2'7, 1%1, Ser. No. 143,229. Divided and this application Aug. 2, 1963,Ser. No.

6 Claims. ct. 29-41 This invention is a division of my applicationSerial Number 148,229, filed October 27, 1961.

This invention relates to hinge means and the manufacture thereof; andmore specifically, to a windshield visor hinge for vehicular use.

Vehicular windshield visors are commonly rotatabiy mounted at each sideof a vehicle windshield. The'visors are adapted for movement from anupper stowed position, substantially parallel to and lying fiat againstthe vehicle roof, to a lower shielding position extending substantiallyvertically in front of the Windshield or side windows. The visors arecommonly mounted on a hinge element which takes the form of asubstantially fiat metal strip having means to fasten the visor thereto.A tubular opening is provided on the hinge element within which a rod,pivotally attached to the vehicle, is frictionally received. The tubularopening has previously taken a variety of forms and has beenmanufactured in a variety of ways. In general, the tubular openingfrictionally receives the pivoted rod and is rotatable thereaboutbetween the upper and lower position. Ideally and theoretically, africtional fit is provi-ded such that the visor will be frictiona-llyretained in the upper position and any intermediate position unless avehicle occupant exerts a rotative force on the visor. Obviously, thevisor must be satisfactorily retained in its upper position duringnormal vehicular operating conditions so that the visor will notinadvertently rotate from the upper position to the lower position andinterfere with the vision of a vehicleoperator. Since it is criticalthat the visor be maintained in the upper position, previous visor hingearrangements having an inherent frictional force differential in variousadjusted positions have been designed to exert a maximum frictionalforce in the upper stowed position.

A type of visor hinge element having frictional force variations ismanufactured by bending portions of a flat metal strip into a tubularconfiguration. The flat metal strip is slotted along an edge on whichthe tube is to be formed to provide a plurality of flat slotted sectionsseparated by transverse slots and integrally connected to a common basesection. Each of the slotted sections are formed into tubularconfiguration by similarly bending the outer edges of the flat slottedsections into a substantially cylindrical form. Since each tube sectionis similarly bent, all of them extend in the same direction andterminate at similar circumferential positions. Accordingly, a slot oropening is formed between the outer edge of each tubular section and thecommon base section to form a. continuous longitudinal slot along oneside of th hinge element. A rod frictionally mounted in the tubularsections requires a substantially different force application to causerotation in one direction as compared with rotation in the otherdirection. Consequently, the frictional binding effect is decreased orlessened depending upon the direction of rotation of the hinge elementrelative to the rod. Since it is necessary and desirable, for safetyreasons, to have the maximum binding effect applied when the visor is inthe upper position, the hinge elements are installed in a particularmanner to obtain that result. Accordingly, a right and left hand hingemust be provided for each vehicle since one hinge element is mounted ona rod element pivoted adjacent the left hand door and extending iatentedJune I, 1965 inwardly therefrom, and the other hinge element is mountedon a rod element pivoted adjacent the right hand vehicle door andextending inwardly therefrom. Therefore, special assembly procedures arerequired to insure that the right type of hinge is placed in the correctposition in the vehicle and associated only with a right or left handvisor element. Furthermore, since a maximum frictional retaining forceis obtained in one position and a 'minimum frictional force is obtainedin another position,

the windshield visor is often undesirably loose in, or close to, thelower position and undesirably tight in, or close to, the upperposition.

Consequently, attempts have been made to design a visor hingearrangement having equal frictional force retaining characteristics inall positions and, in which, an equal minimum amount of force isrequired to move the visor between varying positions. Some attempts havebeen made to produce such a visor hinge from multiple parts. However,such hinges are generally more costly to manufacture and more subject towear in use resulting in undesirable visor looseness. In order to takeadvantage of the economies of manufacture and durability in use of asingle piece friction-type hinge, it has previously been proposed toform such a hinge element by a stamping process. The hinge element ismade from a piece of relatively heavy gauge strip stock which is slottedand formed into op positely extending semi-cylindrical tube portions. Inan attempt to control the undesirable effects of springback, the tubularsections are made relatively short in length and an extended series ofsix or more tubular sections are provided to insure sufficient surfacecontact area with the rod element to frictionally retain the visor inthe adjusted positions. Because of the excessive number of tubularsections and corresponding slotted areas, the strength of the hingeelement is materially reduced and the hinge elements are rathereasilybent in handling prior to assembly, during assembly and insubsequent use. Furthermore, since the tubular sections aresemi-cylindrical in design, assembly of the rod into the tubular openingis more difiicult because of lack of sufficient peripheral support forthe rod until the rod has passed through at least three of thesemi-cylindrical sections. In automatic assembly of rod elements intothe tubular sections, the rod elements become easily misaligned byslight movement away from the confining semi-cylindrical walls of thefirst two tubular sections of the extended series thereof. In assemblyof the visor to the hinge element, a stitching operation is commonlyused to secure the visor to the hinge element. The stitching operationcomprises the insertion of staples through the visor and into the hingeelement. When heavier gauge stock must be utilized for the hinge elementin an attempt to control springback and to provide additional beamstrength, the stitching operation becomes more difficult. Thus, in manyrespects a hinge element manufactured by a stamping process and havingreversely bent semi-cylindrical tubular portions is unsatisfactory. Thisinvention relates specifically to a new and improved tubular hinge form,and the method and apparatus for manufacturing the same.

It is, therefore, a principal objective of the present invention. toprovide a new and improved visor hinge arrangement producing moresatisfactory results in use and being more economical to manufacture. Afurther object is to provide hinge means of the frictional locking typehaving uniform frictional locking characteristics in all positions ofadjustment. Another object is to provide avehicular sun visor hingewhich may be manufactured as an integral unit from coil stock of lightergauge steel than previous'hinges and therefore requires less materialand is lighter in weight. Still a further object is to provide a visorhinge having improved strength character- J istics and having a designfacilitating assembly operations and reducing assembly costs.

Another principal object of the present invention is to provide a hingeelement manufactured by a roll forming operation from a single sheet ofmetal and having oppositely bent flange portions which form a tubularconduit. In this connection, it is another object to provide a methodand means to roll form a tubular passage having a plurality ofoppositely bent sections, each of which extend circumferentiallyapproximately 360 in opposite directions. A still further object is toprovide a new and improved method of roll forming a tubular passage in asingle piece of sheet material. Similarly, another object is to providenovel apparatus for carrying out the aforementioned method.

In order to accomplish the aforementioned purposes and objects, frictiontype hinge means has been designed which provides equal frictionalcharacteristics in all hinge positions and which provides a maximumfrictional surface engagement area. In general, the hinge means isformed from a sheet metal blank having a series of transverse slotsformed at predetermined intervals along one edge to divide the blankinto a plurality of slotted sections integrally connected by a commonbase section. Alternate slotted sections are oppositely bent and formedinto tubular portions of cylindrical shape and equal diameter located incoaxial alignment with one another. Accordingly, each of the slottedsections is bent circumferentially approximately 360 so that the outerend of each slotted section is displaced circumferentially approximately360 and terminates closely adjacent the base section of the blank fromwhich it was bent. The total inner peripheral surface area of all of thetubular sections bent in one direction is approximately equal to thetotal inner peripheral surface area of all of the tubular sections bentin the other direction. Consequently, a hinge arrangement is providedwherein equal frictional forces are applied to a rod, inserted into thetubular sections and frictionally retained thereby, in any adjustedposition regardless of the direction of rotation of the hinge elementabout the rod element.

In order to manufacture the aforedescribed hinge means, a novelmanufacturing method and apparatus have been developed. The novel methodincludes a roll forming operation which provides distinct advantages. Ingeneral, the method of roll forming the hinge means comprises the stepsof:

(l) Continuously moving a strip of coil stock through processingapparatus to form a hinge;

(2) Slotting the edges of the coil stock strip to define a plurality ofslotted sections integrally connected by a common base section;

(3) Simultaneously bending a corner of alternate slotted sections of thecoil stock strip to form an outwardly curved flap thereon;

(4) Passing the coil stock strip over a wedging means which deflects theslotted sections having the outwardly curved flaps to one side of thebase section while the other slotted sections are deflected to the otherside of the base section;

(5) Subsequently passing the coil stock between rollers of a rollingmill and further bending adjacent slotted sections in oppositedirections, and subsequently;

(6) Progressively rolling the oppositely bent slotted sections aroundcurved guide means until substantially cylindrical coaxial tubularportions are formed by each slotted section and each slotted sectiondefines a cylindrical surface having the end thereof lying closelyadjacent the base section.

In general, the manufacturing apparatus includes a 7 press means whichsimultaneously slots the coil stock strip and forms the outwardly curvedflaps on the slotted sections thereof. Guide means and wedging meansreceive the coil stock strip from the press means and guide the stockinto a rolling mill and simultaneously bend alternate slotted sectionsin opposite directions relative to the base section to insure that therollers of the rolling mill form alternate slotted sections in oppositedirections. Guide means are provided in the rolling mill to conduct thecoil stock strip between a plurality of rollers which progressively formthe slotted sections into oppositely extending cylindrical shapes. Theguide means are supported adjacent the coil stock and extend inwardlybetween the oppositely bent slotted sections while each slotted sectionis being gradually bent outwardly and a semi-cylindrical curvature isbeing formed on the innermost portions thereof. After the slottedsections have been outwardly displaced a predetermined amount, the endportions thereof are reversely bent inwardly toward one another tocomplete a cylindrical form. As the end portions are bent inwardly intocylindrical form, the guide means becomes a tapered rod of decreasingdiameter which is internally supported within the slotted sections andextends continuously between the rollers until the tubular opening iscompletely formed.

It is contemplated that some of the principles of the present inventionare applicable to hinge means which may be utilized in otherenvironments than with vehicle visors wherein equal frictional retainingforces are desired in various hinge positions. It is contemplated thatthe frictional retaining forces may be unequalized if desired by varyingthe number of tubular portions or the lengths of the tubular portions sothat the total surface area of engagement of tubular sections extendingin one direction may be varied relative to the total surface area ofengagement of tubular sections extending in the opposite directionwhereby predetermined variations in frictional retaining forces may beobtained in various hinge positions. Furthermore, the method andapparatus for roll forming a tubular passage formed by adjacentoppositely extending, integrally connected, sections may be applied toother articles requiring the same structural features even though theultimate use and function of the particular parts manufactured may beconsiderably different than the subject vehicular visor. Thus, otherobjects and advantages and uses of the principles of the invention willbe apparent, or become ap parent, by reference to the following detaileddescription and the accompanying drawing wherein:

FIGURE 1 is a side elevational view, with portions removed, of a hingeassembly embodying the principles of the present invention;

FIGURE 2 is an end view of the assembly shown in FIGURE 1 taken alongthe line 22;

FIGURE 3 is a sectional view taken along the line 33 in FIGURE 1;

FIGURE 4 is a sectional view taken along the line 4-4 in FIGURE 1;

FIGURE 5 is a diagrammatic illustration of apparatus for manufacturingthe hinge means shown in FIGURE 1;

FIGURE 6 is a side elevational view of a portion of the apparatus shownin FIGURE 5;

FIGURE 7 is a plan view of a portion of a strip of sheet material fromwhich a hinge is formed in an intermediate stage of manufacture;

FIGURE 8 is an enlarged partial view of a portion of the apparatus shownin FIGURE 6;

FIGURE 9 is a sectional view taken along the line 9-9 in FIGURE 6;

FIGURE 10 is a sectional view taken along the line 101tl in FIGURE 6;

FIGURE 11 is a partial sectional view taken along the line 11-11 inFIGURE 6 and showing the configuration of the roller elements and thestrip of sheet material at station No. 1 in FIGURE 5;

FIGURES 12-20 are partial sectional views similar to FIGURE 11 andshowing the configuration of the roller elements and the strip of sheetmaterial at each of the stations 2-10 in FIGURE 5;

FIGURE 21 is a plan view of portions of stations 4,

" and 6 of FIGURE 5 illustrating guide means associated therewith;

FIGS. 22-26 are detail views of portions of guide means provided betweenstations 5 and 6.

Referring now to FIGURES l4, an illustrative Visor hinge means is shownto be formed from a length of sheet material It In the illustrativeembodiment, the sheet material is .024 gauge sheet steel; but Othersizes and kinds of sheet material can also be utilized. The hinge meanscomprises a flange portion 12. which is provided with a longitudinallyextending reinforcement rib 14. In use, a conventional visor member (notshown) is fixedly secured to the flange 12 by staples or any othersuitable fastening means. The upper end of the flanged portion 12terminates in a series of coaxial tubular portions 16, 18, which areseparated from one another by transversely extending slots 22, 24. It isto be understood that additional tubular portions may be provided asdesired although only three are necessary for most visor applications.Eachof the tubular portions is formed from slotted sections 26, 2'8, 39integrally connected by a common base section on the original blank ofsheet material it) as shown in FIGURE 7. The tubular portion 16 isformed by bending the slotted section 26 circumferentially in onedirection to form a cylindrical housing and the tubular portion 18 isformed by bending the slotted section 28 circumferentially in theopposite direction to form a coaxial cylindrical housing of equaldiameter. The tubular portion 20 is formed by bending the slottedsection 30 circumferentially in the same direction as the slottedsection 26. In this manner, alternate tube portions are formed bybending the associated slotted sections of the sheet material blank inopposite directions. The outer ends 32, 34, 36 of the slotted sectionsterminate substantially adjacent the base section 12 so that the innerperipheral surface of each of the tubular portions extends substantially360. The term substantially 360 is intended to include spatialvariations of the end portions relative to the flange portion which mayresult from manufacturing considerations; and, in general, will includevariations between 270 and360".| The end portions 32, 34-, 36 areoutwardly flared to prevent the edges of the end portions from bindingwith rod means to be inserted through the tubular portions.

The visor hinge is adapted to be slidably assembled on a rod means 40 orthe like which is connected at its other end to conventional fasteningmeans (not shown) for securing the visor assembly to the roof of avehicle. The diameter of the tubular portions is less than the diameterof the rod 40 so that an interference fit of approximately between .0l0inch and .014 inch is obtained. The interference fit can be varied toprovide different degrees of tightness as desired. In the assembledposition, the rod 40 has substantially equal frictional peripheralcontact with similarly directed tubular portions. In other words, thesurface contact area between the tubular portion 18 and the rod 40 isapproximately equal to the surface contact area between the tubularportions 16, 20 and the rod 40. Since the tubular portions 16, 20 extendcircumferentially in the same direction, and in the opposite directionto the tubular portion 13, frictional forces developed between the rod40 and the tubular portion of the hinge during rotation of the hingeabout the rod, and in various adjusted positions of the hinge relativeto the rod, will be substantially equal regardless of the direction ofrotation or the position of the hinge. The provision of equal andoppositely directed frictional characteristics during rotation of thevisor and in each of the adjusted visor positions, provides improved0perational results and a distinct advantage over the prior art ashereinbefore described. Since each of the tubular portions issubstantially cylindrical, the rod means 40 is firmly supported aboutmost of its periphery and the number of possible binding edges, whichmight contact the periphery of the rod means and freeze the visor hingein a single position, are eliminated. The substantially completeperipheral surface engagement between the rod 4% and the tubularportions is particularly important during assembly of the rod with thehinge means. In general, such assemblies are automatically accomplishedand the rod is rammed through the tubular portions at a rapid rate. Itinsufficient peripheral contact is provided between the tubular portionsand the rod, the rod may become misaligned relative to the central axisof the tubular portions and bend or otherwise damage the tubularportions during assembly.

The tubular portions 16, 18, 2t and the reinforcement groove 14 areformed in the sheet of material 10 by a roll-forming operation. Theutilization of a roll-forming operation enables the tubular portions tobe formed very closely to specified dimensions so that peripheralcontact between the tubular portions and the rod will be substantiallyequal and uniform around the entire inner periphery of each of thetubular portions and between adjacent tubular portions. A hinge formedby a roll-forming operation provides distinct advantages over previoushinges formed by other types of forming operations, such as a stampingoperation, in which the tendency of the tubular portions to spring backto their original flat configuration is very diflicult to control andcan often'result in unequal peripheral engagement of the tubularportions with the rod means. Another aspect of the present inventionrelates to the manufacture of an integral, one piece, hinge means havinga plurality of adjacent oppositely directed tubular portions whichextend circumferentially substantially 360, by a rollforming operation.

A novel method and apparatus for manufacturing the aforedescn'bed hingemeans is illustrated in FIGURES 5-21. Referring now to FIGURE 5, themanufacturing operation comprises, in general, continuous movement of acontinuous strip of sheet material 10 from a coil of stock (not shown)through punch press means 50, rolling mill means 5-2 and cutoif pressmeans 54. As shown in FIGURE 6, the punch press means 5d comprises aconventional upper platen 56 adapted to be reciprocably driven relativeto a lower platen 58 which is fixedly supported on a base member 6d. Theupper platen 56 carries a plurality of conventional slotting means 62which are adapted to form the slots 22, 24 and locating slots 64, 66 inthe sheet metal strip 16. In addition, a special forming punch 68 islocated above a corresponding spring mounted die plate 70 which isbiased upwardly by spring elements 72 and movable downwardly against thespring elements as the forming punch 68 performs a forming operation onthe continuously moving sheet meta-l strip 10. The forming punch 68,shown in FIGURE 8, is provided With a locating ilang '74 which isadapted to be received within the slot 24 and an upwardly curvedadjacent surface 76 which is adapted to form an outwardly curved flap"/8 on the leading corner 8t) of the slotted section 23. One of theslotting means 62 may be located at 51 along the side of punch 68. Thestrip 10 is moved the distance between the locating fian'ge '74 and'thefirst slotting means 62 between closing movements of the punch press 50so that only alternate flanges are provided with upwardly curved flaps78. The details of the rolling mill and the presses are conventional.The various forming operations performed by the press means 50 and thecutoff press 54 on the continuously moving strip are accommodated byconventional slide mechanism. Since such press operations areconventional and Well known to those skilled in manufacturing, none ofthe conventional apparatus need be described in detail herein.

Referring now toFIGURES 6 and 9, as the strip of sheet material 10 movesfrom the punch press means 50 into the rolling mill 52, the strip passesthrough a guide block 84 which has a substantially flat upper guidesurface 36 adapted to slidably engage and guide the upper surface of thesheet metal strip 10. Wedging and guide means 88 in the form of a blockhaving a substantially flat upper surface 90 adn a downwardly andoutwardly tapered lower surface 92 is fixedly secured relative to themoving sheet metal strip and spaced beneath the upper guide surface 86so that the strip and the slotted sections 26, 31 can pass between theguide surfaces 86, 90. The forward edge 94, shown in FIGURE 6, of thewedging means 38 is tapered inwardly and downwardly to provide aprojection adapted to engage and guide the curved flap 78 downwardlyover the lower surface 92 and thereby bend the slotted section 36downwardly and outwardly relative to the slotted sections 28 and 32along the dashed line 96 in FIGURE 7.

Referring now to FIGURES 6 and 11, rolling mill station No. 1 is shownto comprise an upper roller 11! rotatably driven on a horizontal shaft112 and a lower roller 114 rotatably driven on a parallel shaft 116. Anidle roll 118 is rotatably mounted on a vertical idler shaft 120. Thecontinuously moving strip of sheet material 10 is received between therolls and has a curved portion 122 formed in the base section by therolls 119, 114. The slotted sections 23, 36 are further outwardlydisplaced by the idle roll 113. It is to be understood that theaforedescribed section or" the strip of sheet material shows only theslotted sections 28, 31B; and that the slotted section 26, and anyadditional slotted sections, would have a similar position and beoperated upon in a similar manner. Re-

ferring now to FIGURES 6 and 10, another guide block 126 is fixedlysecured to a support block 128 between the rolls at station No. 1 andstation No. 2. The guide block 126 is provided with upper and lowerintersecting inclined surfaces 13%), 132 which extend inwardly into thepath of movement of the strip of material 10 and are located between theslotted sections. The forward end 136 of the guide extends inwardlyclosely adjacent the idle roll 118 and tapers outwardly therefrom toprovide an additional wedging action between the slotted portions asillustrated in FIGURE 6. The guide 126 terminates closely adjacent anidle roll 140, shown in FIGURE 12. The idle roll 140 has a taperedperipheral surface 142 which further expands the slotted sections awayfrom one another in cooperation with an upper roll 142 and a lower roll144 which form the reinforcement rib 14 and the flange portion 12. Thestrip of material next passes through an upper roll 148 and a lower roll150 at station No. 3 as shown in FIGURE 13. An idle roll 152 at station13 further outwardly displaces the slotted sections.

The flange portion 12 of the strip of material is engaged by similarlyconfigured portion of the rolls 148-150. It is to be understood that allof the succeeding rolls in the rolling mill have identical flangeengaging portions and will not be hereinafter described in any detail.The strip of material passes next to station No. 4, as shown in FIG- URE14, and is engaged by an idle roll 154, and upper and lower rolls 156,158. The rolls at station No. 4 begin to form curved inner surfaces 160,161 on the slotted portions. Referring now to FIGURE 15, the strip ofmaterial is engaged by an upper roll 162 and a lower roll 164. A guideblock 166 having a substantially semicylindrical inner surface 168 isfixedly secured adjacent the path of movement of the strip of materialand extends inwardly between the lower slotted sections and the upperslotted sections. The rolls 162, 164 and the guide block 166 formpartial cylindrical surfaces on each of the slotted sections over aperipheral distance of approximately 90. Referring now to FIGURE 21, aportion 168 of the guide block 166 extends between station No. 5 andstation No. 6. The guide block cross section changes form between thestations from the section of the block having a semicylindrical innersurface as shown in FIGURE to a rod 171) having a cylindrical crosssection. The rod 170 extends through an upper roller 174 and a lowerroller 8 176 at station No. 6. The rollers 174, 176 are adapted toreversely bend the outer ends of each of the slotted portions intoclosed loops as shown in FIGURE 16. An additional guide block 178, shownin FIGURES 21-24, may be provided immediately adjacent the rolls 174,176 and has a tapered leading edge 180 and a curved inner surface 181which is adapted to guide the outer ends of the slotted sections intothe cylindrical cavity defined by the forming rolls 174, 176. The rodportion extends continuously from station No. 6 to the end of therolling mill in the form of a plurality of abutting tapered rod sections180, 182, 184, of gradually reduced diameters. Substantially similarupper and lower roller sets 188, 190, and 192, 194, and 1%, 198, and202, 204 are provided at stations 7 to 10, respectively, and continuethe reverse bending of the slotted sections started at station No. 6,until the outer ends are completely circumferentially displaced aroundthe rod elements and the slotted sections acquire a substantiallycylindrical form as shown in FIG- URE 20. The formed strip of materialleaves the rolling mill 52 and appropriate lengths of the strip aresevered in a conventional manner in the press 54 to obtain individualhinge means having the form illustrated in FIGURES 1-4.

It is contemplated that the particular configurations of the rolls andguide means at the various stations of the rolling mill can be varied toform the desired tubular configurations more quickly or more slowly anduniformly. Accordingly, additional rolling mill stations may beprovided, or in some instances, a lesser number of rolling mill stationsmay be utilized. Other changes in the method and apparatus may beresorted to without departing from the inventive concepts hereinbeforedisclosed. Thus, it is intended to include obvious modifications andchanges in the details of the manufacturing method and apparatus, andother modifications, within the scope of the present invention, asdefined by the appended claims, except insofar as limited by the priorart.

What is claimed is:

1. A method of manufacture of a hinge element or the like having aplurality of separate oppositely bent circumferentially extendingflanges simultaneously formed in a strip of coil stock by roll-formingand comprising, in series, the steps of:

('1) slotting the coil stock to (2) forming an outwardly curved flap onone corner of alternate flanges;

(3) wedging adjacent flanges in opposite directions to define an acuteangle therebetween by inserting gedge means along the curve surface ofsaid curved (4) gradually and progressively enlarging the angle betweenalternate flanges by successive wedging operations;

(5) moving said coil stock along back up means secured outwardly of andextending inwardly between said flanges and having an inner curvedsurface abuttingly engaged therewith;

(6) progressively changing said back up means to a tapered rod havingcircular cross sections of decreasing diameter and located completelywithin and between the confines of said flanges; and

(7) progressively rolling said flanges about said back up means untilsaid alternate flanges extend in opposite directions substantially 360to define a continuous coaxial cavity.

2. Apparatus for roll-forming adjacent slotted sections of a strip ofsheet material in opposite directions into a cylindrical shape forming acoaxial tubular cavity extending between said slotted sections, andcomprising: means to slot said strip of sheet material to form saidslotted sections, means to bend a portion of alternate slotted sectionsoutwardly away from the other slotted sections, means engageable withthe outwardly bent portion of alternate slotted sections to bendadjacent slotted provide said separate sections in opposite directions,and common means to roll-form each of said slotted sections intocylindrical shapes forming said coaxial tubular cavity.

3. The apparatus as defined in claim 2 and wherein guide means areprovided to support said strip of material during roll-forming of saidcylindrical shapes, a first portion of said guide means being fixedlysecured outwardly of and extending into surface engagement with portionsof the inner periphery of said slotted sections, and said first portionof said guide means gradually tapering into cylindrical means locatedinwardly of and supported entirely within said flanged portions duringformation of said cylindrical shapes.

4. Roll-forming apparatus for forming a tubular cavity in a blank ofmaterial which comprises a plurality of separated sections integrallyconnected to a common base; and comprising: means to deflect alternateseparated sections relative to the other separated sections, means tobend said alternate separated sections outwardly away from said otherseparated sections, subsequent means to roll-form a semi-cylindricalsurface along the inner surfaces of said separated sections nextadjacent said cornmon base member, and means to thereafter reverselybend the outer surfaces of said separated sections toward and past oneanother into a cylindrical form forming a continuation of said firstmentioned semi-cylindrical surface and defining therewith a cylindricalsurface extending circumferentially substantially 360.

5. A method of manufacture of a hinge element or the like having aplurality of separate oppositely bent circumferentially extendingflanges simultaneously formed in a a strip of coil stock by roll-formingand comprising, in

series, the steps of:

(l) slotting the coil stock to provide said separate flanges;

(2) forming an outwardly curved flap on one corner of alternate flanges;

(3) wedging adjacent flanges in opposite directions to define an acuteangle therebetween by inserting wedge means along the curved'surface ofsaid curved flap;

(4) gradually and progressively enlarging the angle between alternateflanges by successive wedging operations;

(5) and forming a curved cylindrical surface along the inner facingsurfaces of said flanges extending substantially 360 from one side ofthe coil stock to the opposite side thereof whereby alternate flangesterminate on opposite sides of said coil stock.

6. The method of roll-forming a hinge having a tubular portion andcomprising the step of:

(l) continuously moving a strip of coil stock through processingapparatus to form a hinge;

(2) slotting the edges of the coil stock strip to define a plurality ofslotted sections integrally connected by a common base section;

(3) simultaneously bending a corner of alternate slotted sections of thecoil stock strip to form an outwardly curved flap thereon;

(4) passing the coil stock strip over a wedging means which deflects theslotted sections having the outwardly curved flaps to one side of thebase section while the other slotted sections are deflected to the otherside of the base section;

(5) subsequently passing the coil stock between rollers of a rollingmill and further bending adjacent slotted sections in oppositedirections, and subsequently;

(6) progressively rolling the oppositely bent slotted sections aroundcurved guide means until substantially cylindrical coaxial tubularportions are formed by each slotted section and each slotted sectiondefines a cylindrical surface having the end thereof lying closelyadjacent the base section.

References Cited by the Examiner UNITED STATES PATENTS 442,656 12/90Whittlesey 29'l1 738,266 9/03 Weiss 29l1 1,604,229 10/26 Kellogg 2911 40RICHARD H. EANES, JR., Primary Examiner.

1. A METHOD OF MANUFACTURE OF A HINGE ELEMENT OR THE LIKE HAVING APLURALITY OF SEPARATE OPPOSITELY BENT CIRCUMFERENTIALLY EXTENDINGFLANGES SIMULTANEOUSLY FORMED IN A STRIP OF COIL BY ROLL-FORMING ANDCOMPRISING, IN SERIES, THE STEPS OF: (1) SLOTTING THE COIL STOCK TOPROVIDE SAID SEPARATE FLANGES; (2) FORMING AN OUTWARDLY CURVED FLAP ONONE CORNER OF ALTERNATE FLANGES; (3) WEDGING ADJACENT FLANGES INOPPOSITE DIRECTIONS TO DEFINE AN ACUTE ANGLE THEREBETWEEN BY INSERTINGWEDGE MEANS ALONG THE CURVE SURFACE OF SAID CURVED FLAPS; (4) GRADUALLYAND PROGRESSIVELY ENLARGING THE ANGLE